package overlay

import (
	"io"
	"os"
	"path"
	"sort"
	"testing"

	"github.com/stretchr/testify/assert"
	warewulfconf "github.com/warewulf/warewulf/internal/pkg/config"
	"github.com/warewulf/warewulf/internal/pkg/node"
	"github.com/warewulf/warewulf/internal/pkg/testenv"

	"github.com/warewulf/warewulf/internal/pkg/util"
)

func Test_OverlayMethods(t *testing.T) {
	env := testenv.New(t)
	defer env.RemoveAll(t)

	// Setup test data
	sitedir := "/var/lib/warewulf/overlays/"
	distdir := "/usr/share/warewulf/overlays/"

	env.WriteFile(t, path.Join(sitedir, "siteonly/rootfs/testfile"), "a site overlay")
	env.WriteFile(t, path.Join(distdir, "distonly/rootfs/testfile"), "a distribution overlay")
	env.WriteFile(t, path.Join(sitedir, "legacy/testfile"), "a legacy overlay")
	env.WriteFile(t, path.Join(sitedir, "both/rootfs/testfile"), "the site version")
	env.WriteFile(t, path.Join(distdir, "both/rootfs/testfile"), "the distribution version")

	var tests = map[string]struct {
		name    string
		path    string
		rootfs  string
		file    string
		content string
		exists  bool
		isSite  bool
		isDist  bool
	}{
		"site overlay": {
			name:    "siteonly",
			path:    path.Join(sitedir, "siteonly"),
			rootfs:  path.Join(sitedir, "siteonly/rootfs"),
			file:    path.Join(sitedir, "siteonly/rootfs/testfile"),
			content: "a site overlay",
			exists:  true,
			isSite:  true,
			isDist:  false,
		},
		"distribution overlay": {
			name:    "distonly",
			path:    path.Join(distdir, "distonly"),
			rootfs:  path.Join(distdir, "distonly/rootfs"),
			file:    path.Join(distdir, "distonly/rootfs/testfile"),
			content: "a distribution overlay",
			exists:  true,
			isSite:  false,
			isDist:  true,
		},
		"overlapping overlay": {
			name:    "both",
			path:    path.Join(sitedir, "both"),
			rootfs:  path.Join(sitedir, "both/rootfs"),
			file:    path.Join(sitedir, "both/rootfs/testfile"),
			content: "the site version",
			exists:  true,
			isSite:  true,
			isDist:  false,
		},
		"legacy overlay": {
			name:    "legacy",
			path:    path.Join(sitedir, "legacy"),
			rootfs:  path.Join(sitedir, "legacy"),
			file:    path.Join(sitedir, "legacy/testfile"),
			content: "",
			exists:  true,
			isSite:  true,
			isDist:  false,
		},
		"missing overlay": {
			name:    "absent",
			path:    path.Join(sitedir, "absent"),
			rootfs:  path.Join(sitedir, "absent/rootfs"),
			file:    path.Join(sitedir, "absent/rootfs/testfile"),
			content: "",
			exists:  false,
			isSite:  true,
			isDist:  false,
		},
	}

	for name, tt := range tests {
		t.Run(name, func(t *testing.T) {
			overlay := GetOverlay(tt.name)
			assert.Equal(t, tt.name, overlay.Name())
			assert.Equal(t, env.GetPath(tt.path), overlay.Path())
			assert.Equal(t, env.GetPath(tt.rootfs), overlay.Rootfs())
			assert.Equal(t, env.GetPath(tt.file), overlay.File("testfile"))
			if tt.content != "" {
				buffer, err := os.ReadFile(overlay.File("testfile"))
				assert.NoError(t, err)
				assert.Equal(t, tt.content, string(buffer))
			}
			assert.Equal(t, tt.exists, overlay.Exists())
			assert.Equal(t, tt.isSite, overlay.IsSiteOverlay())
			assert.Equal(t, tt.isDist, overlay.IsDistributionOverlay())
		})
	}
}

var buildOverlayTests = []struct {
	description string
	nodeName    string
	context     string
	overlays    []string
	image       string
	contents    []string
	hasFiles    bool
}{
	{
		description: "if no node, context, or overlays are specified then no overlay image is generated",
		nodeName:    "",
		context:     "",
		overlays:    nil,
		image:       "",
		contents:    nil,
	},
	{
		description: "if only node is specified then no overlay image is generated",
		nodeName:    "node1",
		context:     "",
		overlays:    nil,
		image:       "",
		contents:    nil,
	},
	{
		description: "if only context is specified then context named image is generated",
		nodeName:    "",
		context:     "system",
		overlays:    nil,
		image:       "__SYSTEM__.img",
		contents:    nil,
	},
	{
		description: "if an overlay is specified without a node, then the overlay is built directly in the overlay directory",
		nodeName:    "",
		context:     "",
		overlays:    []string{"o1"},
		image:       "o1.img",
		contents:    []string{"o1.txt"},
	},
	{
		description: "if multiple overlays are specified without a node, then the combined overlay is built directly in the overlay directory",
		nodeName:    "",
		context:     "",
		overlays:    []string{"o1", "o2"},
		image:       "o1-o2.img",
		contents:    []string{"o1.txt", "o2.txt"},
	},
	{
		description: "if a single node overlay is specified, then the overlay is built in a node overlay directory",
		nodeName:    "node1",
		context:     "",
		overlays:    []string{"o1"},
		image:       "node1/o1.img",
		contents:    []string{"o1.txt"},
	},
	{
		description: "if multiple node overlays are specified, then the combined overlay is built in a node overlay directory",
		nodeName:    "node1",
		context:     "",
		overlays:    []string{"o1", "o2"},
		image:       "node1/o1-o2.img",
		contents:    []string{"o1.txt", "o2.txt"},
	},
	{
		description: "if no node system overlays are specified, then context pointed overlay is generated",
		nodeName:    "node1",
		context:     "system",
		overlays:    nil,
		image:       "node1/__SYSTEM__.img",
		contents:    nil,
	},
	{
		description: "if no node runtime overlays are specified, then context pointed overlay is generated",
		nodeName:    "node1",
		context:     "runtime",
		overlays:    nil,
		image:       "node1/__RUNTIME__.img",
		contents:    nil,
	},
	{
		description: "if a single node system overlay is specified, then a system overlay image is generated in a node overlay directory",
		nodeName:    "node1",
		context:     "system",
		overlays:    []string{"o1"},
		image:       "node1/__SYSTEM__.img",
		contents:    []string{"o1.txt"},
	},
	{
		description: "if a single node runtime overlay is specified, then a runtime overlay image is generated in a node overlay directory",
		nodeName:    "node1",
		context:     "runtime",
		overlays:    []string{"o1"},
		image:       "node1/__RUNTIME__.img",
		contents:    []string{"o1.txt"},
	},
	{
		description: "if multiple node system overlays are specified, then a system overlay image is generated with the contents of both overlays",
		nodeName:    "node1",
		context:     "system",
		overlays:    []string{"o1", "o2"},
		image:       "node1/__SYSTEM__.img",
		contents:    []string{"o1.txt", "o2.txt"},
	},
	{
		description: "if multiple node runtime overlays are specified, then a runtime overlay image is generated with the contents of both overlays",
		nodeName:    "node1",
		context:     "runtime",
		overlays:    []string{"o1", "o2"},
		image:       "node1/__RUNTIME__.img",
		contents:    []string{"o1.txt", "o2.txt"},
	},
}

func Test_BuildOverlay(t *testing.T) {
	conf := warewulfconf.Get()
	overlayDir, overlayDirErr := os.MkdirTemp(os.TempDir(), "ww-test-overlay-*")
	assert.NoError(t, overlayDirErr)
	defer os.RemoveAll(overlayDir)
	conf.Paths.WWOverlaydir = overlayDir
	assert.NoError(t, os.Mkdir(path.Join(overlayDir, "o1"), 0700))
	{
		_, err := os.Create(path.Join(overlayDir, "o1", "o1.txt"))
		assert.NoError(t, err)
	}
	assert.NoError(t, os.Mkdir(path.Join(overlayDir, "o2"), 0700))
	{
		_, err := os.Create(path.Join(overlayDir, "o2", "o2.txt"))
		assert.NoError(t, err)
	}

	for _, tt := range buildOverlayTests {
		nodeInfo := node.NewNode(tt.nodeName)
		t.Run(tt.description, func(t *testing.T) {
			provisionDir, provisionDirErr := os.MkdirTemp(os.TempDir(), "ww-test-provision-*")
			assert.NoError(t, provisionDirErr)
			defer os.RemoveAll(provisionDir)
			conf.Paths.WWProvisiondir = provisionDir

			err := BuildOverlay(nodeInfo, tt.context, tt.overlays)
			assert.NoError(t, err)
			if tt.image != "" {
				image := path.Join(provisionDir, "overlays", tt.image)
				assert.FileExists(t, image)
				sort.Strings(tt.contents)
				files, err := util.CpioFiles(image)
				assert.NoError(t, err)
				sort.Strings(files)
				assert.Equal(t, tt.contents, files)
			} else {
				dirName := path.Join(provisionDir, "overlays", tt.nodeName)
				isEmpty := dirIsEmpty(t, dirName)
				assert.True(t, isEmpty, "%v should be empty, but isn't", dirName)
			}
		})
	}
}

// Although these tests specify system and runtime overlays for the
// nodes, these overlays define the overlays that are defined in the
// configuration. BuildAllOverlays doesn't receive these as arguments,
// but builds all the overlays that are configured on the given node.
var buildAllOverlaysTests = []struct {
	description     string
	nodes           []string
	systemOverlays  [][]string
	runtimeOverlays [][]string
	createdOverlays []string
}{
	{
		description:     "empty input creates no overlays",
		nodes:           nil,
		systemOverlays:  nil,
		runtimeOverlays: nil,
		createdOverlays: nil,
	},
	{
		description:     "a node with no overlays creates default system/runtime overlays",
		nodes:           []string{"node1"},
		systemOverlays:  [][]string{{"o1"}},
		runtimeOverlays: [][]string{{"o1"}},
		createdOverlays: []string{"node1/__SYSTEM__.img.gz", "node1/__RUNTIME__.img.gz"},
	},
	{
		description:     "multiple nodes with no overlays creates default system/runtime overlays",
		nodes:           []string{"node1", "node2"},
		systemOverlays:  [][]string{{"o1"}, {"o2"}},
		runtimeOverlays: [][]string{{"o1"}, {"o2"}},
		createdOverlays: []string{"node1/__SYSTEM__.img.gz", "node1/__RUNTIME__.img.gz", "node2/__SYSTEM__.img.gz", "node2/__RUNTIME__.img.gz"},
	},
	{
		description:     "a system overlay for a node generates a system overlay for that node",
		nodes:           []string{"node1"},
		systemOverlays:  [][]string{{"o1"}},
		runtimeOverlays: nil,
		createdOverlays: []string{"node1/__SYSTEM__.img.gz"},
	},
	{
		description:     "two nodes with different system overlays generates a system overlay for each node",
		nodes:           []string{"node1", "node2"},
		systemOverlays:  [][]string{{"o1"}, {"o1", "o2"}},
		runtimeOverlays: nil,
		createdOverlays: []string{"node1/__SYSTEM__.img.gz", "node2/__SYSTEM__.img.gz"},
	},
	{
		description:     "two nodes with a single runtime overlay generates a runtime overlay for the first node",
		nodes:           []string{"node1"},
		systemOverlays:  nil,
		runtimeOverlays: [][]string{{"o1"}},
		createdOverlays: []string{"node1/__RUNTIME__.img.gz"},
	},
	{
		description:     "two nodes with different runtime overlays generates a system overlay for each node",
		nodes:           []string{"node1", "node2"},
		systemOverlays:  nil,
		runtimeOverlays: [][]string{{"o1"}, {"o1", "o2"}},
		createdOverlays: []string{"node1/__RUNTIME__.img.gz", "node2/__RUNTIME__.img.gz"},
	},
	{
		description:     "a node with both a runtime and system overlay generates an image for each",
		nodes:           []string{"node1"},
		systemOverlays:  [][]string{{"o1"}},
		runtimeOverlays: [][]string{{"o2"}},
		createdOverlays: []string{"node1/__RUNTIME__.img.gz", "node1/__SYSTEM__.img.gz"},
	},
	{
		description:     "two nodes with both runtime and system overlays generates each image for each node",
		nodes:           []string{"node1", "node2"},
		systemOverlays:  [][]string{{"o1"}, {"o1", "o2"}},
		runtimeOverlays: [][]string{{"o2"}, {"o2"}},
		createdOverlays: []string{"node1/__RUNTIME__.img.gz", "node1/__SYSTEM__.img.gz", "node2/__RUNTIME__.img.gz", "node2/__SYSTEM__.img.gz"},
	},
}

func Test_BuildAllOverlays(t *testing.T) {
	conf := warewulfconf.Get()
	overlayDir, overlayDirErr := os.MkdirTemp(os.TempDir(), "ww-test-overlay-*")
	assert.NoError(t, overlayDirErr)
	defer os.RemoveAll(overlayDir)
	conf.Paths.WWOverlaydir = overlayDir
	assert.NoError(t, os.Mkdir(path.Join(overlayDir, "o1"), 0700))
	assert.NoError(t, os.Mkdir(path.Join(overlayDir, "o2"), 0700))

	for _, tt := range buildAllOverlaysTests {
		t.Run(tt.description, func(t *testing.T) {
			provisionDir, provisionDirErr := os.MkdirTemp(os.TempDir(), "ww-test-provision-*")
			assert.NoError(t, provisionDirErr)
			defer os.RemoveAll(provisionDir)
			conf.Paths.WWProvisiondir = provisionDir

			var nodes []node.Node
			for i, nodeName := range tt.nodes {
				nodeInfo := node.NewNode(nodeName)
				if tt.systemOverlays != nil {
					nodeInfo.SystemOverlay = tt.systemOverlays[i]
				}
				if tt.runtimeOverlays != nil {
					nodeInfo.RuntimeOverlay = tt.runtimeOverlays[i]
				}
				nodes = append(nodes, nodeInfo)
			}
			err := BuildAllOverlays(nodes)
			assert.NoError(t, err)
			if tt.createdOverlays == nil {
				dirName := path.Join(provisionDir, "overlays")
				assert.True(t, dirIsEmpty(t, dirName), "%v should be empty, but isn't", dirName)
			}
			for _, overlayPath := range tt.createdOverlays {
				assert.FileExists(t, path.Join(provisionDir, "overlays", overlayPath))
			}
		})
	}
}

var buildSpecificOverlaysTests = []struct {
	description string
	nodes       []string
	overlays    []string
	images      []string
	succeed     bool
}{
	{
		description: "building no overlays for no nodes generates no error and no images",
		nodes:       nil,
		overlays:    nil,
		images:      nil,
		succeed:     true,
	},
	{
		description: "building no overlays for a node generates no error and no images",
		nodes:       []string{"node1"},
		overlays:    nil,
		images:      nil,
		succeed:     true,
	},
	{
		description: "building no overlays for two nodes generates no error and no images",
		nodes:       []string{"node1", "node2"},
		overlays:    nil,
		images:      nil,
		succeed:     true,
	},
	{
		description: "building an overlay for a node generates an overlay image in that node's overlay directory",
		nodes:       []string{"node1"},
		overlays:    []string{"o1"},
		images:      []string{"node1/o1.img"},
		succeed:     true,
	},
	{
		description: "building an overlay for two nodes generates an overlay image in each node's overlay directory",
		nodes:       []string{"node1", "node2"},
		overlays:    []string{"o1"},
		images:      []string{"node1/o1.img", "node2/o1.img"},
		succeed:     true,
	},
	{
		description: "building multiple overlays for a node generates an overlay image for each overlay in the node's overlay directory",
		nodes:       []string{"node1"},
		overlays:    []string{"o1", "o2"},
		images:      []string{"node1/o1.img", "node1/o2.img"},
		succeed:     true,
	},
	{
		description: "building multiple overlays for two nodes generates an overlay image for each overlay in each node's overlay directory",
		nodes:       []string{"node1", "node2"},
		overlays:    []string{"o1", "o2"},
		images:      []string{"node1/o1.img", "node1/o2.img", "node2/o1.img", "node2/o2.img"},
		succeed:     true,
	},
}

func Test_BuildSpecificOverlays(t *testing.T) {
	conf := warewulfconf.Get()
	overlayDir, overlayDirErr := os.MkdirTemp(os.TempDir(), "ww-test-overlay-*")
	assert.NoError(t, overlayDirErr)
	defer os.RemoveAll(overlayDir)
	conf.Paths.WWOverlaydir = overlayDir
	assert.NoError(t, os.Mkdir(path.Join(overlayDir, "o1"), 0700))
	assert.NoError(t, os.Mkdir(path.Join(overlayDir, "o2"), 0700))

	for _, tt := range buildSpecificOverlaysTests {
		t.Run(tt.description, func(t *testing.T) {
			provisionDir, provisionDirErr := os.MkdirTemp(os.TempDir(), "ww-test-provision-*")
			assert.NoError(t, provisionDirErr)
			defer os.RemoveAll(provisionDir)
			conf.Paths.WWProvisiondir = provisionDir

			var nodes []node.Node
			for _, nodeName := range tt.nodes {
				nodeInfo := node.NewNode(nodeName)
				nodes = append(nodes, nodeInfo)
			}
			err := BuildSpecificOverlays(nodes, tt.overlays)
			if !tt.succeed {
				assert.Error(t, err)
			} else {
				assert.NoError(t, err)
				for _, image := range tt.images {
					assert.FileExists(t, path.Join(provisionDir, "overlays", image))
				}
			}
		})
	}
}

func dirIsEmpty(t *testing.T, name string) bool {
	f, err := os.Open(name)
	if err != nil {
		t.Log(err)
		return true
	}
	defer f.Close()

	dirnames, err2 := f.Readdirnames(1)
	if err2 == io.EOF {
		t.Log(err2)
		return true
	}
	t.Log(dirnames)
	return false
}